The Empress Kadaena (Iruaric: "Empress", "slayer") was the last ruler of the imperial line that ended the First Era of Shadow World history. The K'ta'viiri family (Ir. "Lords of Essaence") were an extremely powerful group of humanoids on the scale of demi-gods, until a civil war broke out between Kadaena and her rebellious cousin Utha, who wished to end the wanton destruction of her wicked rule. The war was begun as a result of Kadaena performing extreme extra-planar experiments on Lornon (Charon), forging an artificial plane that was coexistent with the moon, which she used as a hidden keep to invent her hideous monstrosities. Utha was the father of Andraax, who founded the Loremasters and Library of Biblia, and slayed the father of Lorgalis in the Second Era.
Kadaena was almost invincible due to the Shadowstone, an immensely powerful artifact she wore around her neck. She had a vast army of dark races such as orcs and trolls which she had created through foul experimentation, as well as constructs she invented including the vruul, and hordes of demonic entities from other planes of existence. The servants of the Shadow were said to have created the first of the Great Demons, and Kadaena was known to use Ordainers and "Flamesouls" as bodyguards. Some Loremasters even speculated that the Dark Gods may have first come into being as Lord of Essaence experiments with creating non-corporeal life.
There were very few survivors, both sides were almost wiped out. The world was virtually destroyed. Finally, Utha decapitated Kadaena before the Gates of the Void. The Void was sealed with two powerful gemstones floating over ornate pedestals, one at each pole of the world, called the Eyes of Utha. While the first age cataclysm in the modern Elanthian history was different, these were essentially the same as The Rift and the Eyes of Koar. They were designed to shield the world from the radiations of the inter-dimensional rift, subdue Flow storms, and prevent easy access by malevolent extra-dimensional entities. They also made the Eastern hemisphere inaccessible, which is not true in Elanthia.
Kadaena had a daughter named V'rama Vair who regained consciousness in 2000 Second Era. She ruled an island in south-west Jaiman that had been a stronghold of Kadaena, under the patronage of the dark goddess Eorgina (Orgiana) whose identity was conflated with Kadaena in their culture. Her rule ended shortly after the I.C.E. Age version of Eorgina was banished to the Black Hel by the Lords of Liabo in 6800 Second Era. The Dark Gods returned to the world early in the Second Era, and were forced back to Lornon in the archaic history at the end of the Wars of Dominion. Her surviving followers, such as Lorgalis, worked with them and servants of the Unlife.
Though no one corresponding to Kadaena per se exists in Elanthian history, Eorgina strongly resembles her, and was given her role by unleashing the Ur-Daemon on the Drakes. Kadaena has nothing in common with Gosaena. The juxtaposition of Lorminstra and Empress Kadaena on The Graveyard gate would have been considered blasphemous in its original context, effectively saying souls are "lost to the demonic" rather than passing through the Gates of Oblivion. The Void was the one key that "must never be used" on the Gates. The Graveyard gate appears to be in flames due to the corrosion of iron, probably symbolizing The Black Hel with Kadaena as the "Guardian of the Forbidden." The false sarcophagus of Kadaena in the royal estate on that isle guarded the actual portal leading to the Black Hel. There were six locks sealing this portal, and there were six keys to Oblivion. Hence, the Phantom Gatekeeper, mocking Lorminstra.